Which Wood Is Best For An Elevated Bed Garden?

The best wood for raised beds is untreated and naturally rot-resistant, such as cedar, redwood, cypress, black locust, and osage orange. These materials last for multiple years without leaching harmful chemicals into the soil. Pressure-treated wood is safe for use in vegetable gardens, depending on your needs, budget, and preferences. Cedar is a popular choice for raised beds due to its excellent natural resistance.

When choosing wood for raised garden beds, look for pieces 1-2 inches thick and use untreated wood to prevent harmful chemicals from leaching into the soil. Rot-resistant wood, like cedar, is a great choice as it will help your raised garden bed last much longer. Modern pressure-treated wood is supposed to be safe for raised beds, but avoid ground contact rated wood.

Cypress is the most commonly used type of wood for raised beds, as it is largely resistant to rot and termites and is relatively easy to find. Other high-quality choices for outdoor construction projects include white cedar, yellow cedar, and juniper. Timber suitable for in-ground use is typically H4 treated pine.

For an alternative to traditional CCA treated wood, use naturally water- and rot-resistant woods such as untreated hemlock or cedar, which last significantly longer. The steps for building raised beds include Cedar, Black locust, Cypress Spruce, Douglas Fir Redwood Oak Pine, and other wood types.

Is it OK to use treated lumber for raised garden beds?

John Harrison, President of JRH Toxicology, states that pressure treated wood for raised bed or box gardening is safe for adults and children in terms of the plants grown and used in these containers. He explains that most chemicals in consumer products have a toxicity and most are very low, so they are not a problem, especially those regulated by the federal government. This is also the case with currently registered wood preservatives that contain copper, which is considered an essential trace element for human and plant life.

Dr. Scott Leavengood, Associate Professor College of Forestry at Oregon State University and Director of the Oregon Wood Innovation Center, authored an article for the OSU Extension Service, stating that the consensus among researchers is that the low levels of chemicals in preservative treated wood that leach out of the wood into the soil are likely to be taken up by the plants only in very small amounts. There has been no evidence to suggest that the level of the chemicals is significant enough to be of concern for human health.

In a 2014 study, wood research scientists Love, Gardner, and Morrell at Oregon State University found that copper levels were not higher in roots or tubers of radishes, carrots, and potatoes compared to beds constructed from untreated wood. They also suggest that when people are concerned about the migration of wood preservatives, they can use polyethylene (plastic) to line the inside of the planter, which can extend the life of the preserved wood and help keep the raised bed garden soil within the bed area.

How long will a treated wood raised bed last?

Raised beds are typically made from lumber, with pine and cedar being the most durable options. Avoid using redwood, an endangered species. To extend the bed’s lifespan, paint or seal the outside but avoid coating the sides that contact the soil. Pressure treated lumber (ACQ) is safe for raised beds but should be avoided due to its copper and fungicide treatment. Railroad ties are not suitable due to their creosote content.

Does a wooden raised bed need a liner?

It is recommended that WoodBlocX raised beds be fully lined with the inclusion of the base and buttresses in order to create an environment conducive to soil retention and to facilitate drainage. This is particularly important when the beds are constructed on patios, paving, concrete, or tarmac. In the event that the ground is of a hard nature, it is advisable to introduce a drainage layer prior to the addition of soil. This may be achieved through the use of materials such as pea gravel, sand, rubble, or small stones.

Is pine ok for raised beds?

White pine and yellow pine are both suitable for raised garden beds, but they have distinct advantages. White pine is a softer, lightweight, and easy-to-work with pale color and a natural, rustic look. It also contains natural oils that make it resistant to decay and insect damage. Yellow pine, on the other hand, is harder, more durable, and more resistant to decay and insect damage. It’s suitable for raised garden beds exposed to moisture and pests, but may be more difficult to work with and may not have the same natural aesthetic qualities.

How to prevent raised beds from rotting?

To enhance the durability of your wooden raised bed, use a safe wood treatment made from Eco Wood Treatment’s mineral powder. This 100% natural and organic substance won’t leave harmful residue in the soil and won’t fade, wear off, or peel. Dilute the powder with water and apply it directly to the wood inside the bed. Applying once will provide years of protection. Other non-toxic options include Valhalla Wood Preservative and Hope’s 100 Pure Tung Oil, which are natural wood sealers. One 2-ounce packet covers about 150 square feet of wood.

What is the best non toxic wood for raised beds?

The author recommends using naturally water- and rot-resistant woods like untreated hemlock or cedar for beds, as they last longer and avoid contamination risks. They eventually succumb to weather damage but only need occasional replacements every few seasons. Home gardeners should replace timbers only when they are at least 6 or 7 years old, as they don’t all go at once. The timbers are structurally sound, and even losing a board doesn’t significantly impact the entire structure once a raised bed is established. The author’s own beds are made of hemlock, which is at least 6 or 7 years old.

Is plywood safe for raised beds?

The six-mil plastic lining of the beds serves to protect against sun exposure, while the water in the soil is utilized to maintain its structural integrity.

How to protect wood in raised garden beds?

To ensure the longevity of your raised bed, consider using eco-friendly wood treatments like linseed oil or beeswax. Lining between the bed and soil can protect the wood, but it may not prevent water seepage. Instead, use a wood preservative-lined lining. A mineral-based preservative can add a silvery patina when dried. If you don’t want the color of the bed to change, treat the interior and leave the exterior untreated.

This will still provide years of durability with more durable wood like cedar. For pine, which is less resistant to rot and decay, treat both the inside and outside. The Eco Restore Wood Treatment is a popular choice for raised beds.

What material is best for raised garden beds?

To minimize soil contact with treated wood in raised beds, paint the wood with exterior latex paint, treat it with a semi-transparent oil-based stain, and apply a heavy plastic liner between the treated wood frame and your garden soil. Build your raised bed with decay-resistant wood like cedar, black cherry, oak, black locust, Osage orange, or redwood, and use non-wood materials like stones, concrete blocks, bricks, or synthetic lumber.

Pressure-treated wood is the most widely available type of wood preservative for residential use, but it contains arsenic and is considered low in toxicity. Research from Oregon State University showed that pressure-treated lumber does increase soil copper concentrations by a minor amount, but only within 1 inch of the raised-bed edge. Their study found no increase in copper concentration in plants grown in raised beds made with pressure-treated lumber. If you have concerns about using MCA-treated wood, paint or stain the wood, use a heavy plastic liner between the wood and your soil, or use a non-wood building material (e. g., stones, bricks).

Cement blocks are safe to use for raised gardens, but they are made with cement and fine aggregates such as sand or small stones, often including fly ash, a byproduct of burning coal and containing heavy metals and other hazardous waste. Labels do not provide specific information on the aggregate used in the manufacture of the block, and there is little research data on this topic. If you plan to use blocks as a raised bed material and are concerned about potential risks, seal the blocks with polymer paint or choose another material.

What should you not put in a raised garden bed?

Raised beds are ideal for growing a wide variety of edible plants, but not all plants can or should be grown in them. Some plants grow too large for raised beds, such as potatoes, asparagus, artichokes, rhubarb, corn, wheat, rice, and winter squash. Raised beds can be challenging to maintain due to the need for ladders, which can be dangerous for harvesting plants. It is essential to consider the specific needs of each plant when choosing a raised bed, as not all plants can thrive in raised beds. Therefore, it is essential to carefully consider the type of plant and the space available for each plant to ensure the best growth and care.

What type of wood should I use for a raised garden bed?

Cedar and redwood are resistant to moisture, but their cost and scarcity make them impractical for many applications. While hemlock, fir, and pine are suitable for use in raised beds, they lack the durability to withstand extended use. The use of pressure-treated lumber is a topic that is the subject of considerable debate.